2.58

यदा संहरते चायं कूर्मोऽङ्गानीव सर्वशः ।
इन्द्रियाणीन्द्रियार्थेभ्यस्तस्य प्रज्ञा प्रतिष्ठिता ॥

yadā saṃharate cāyaṃ kūrmo 'ṅgānīva sarvaśaḥ
indriyāṇīndriyārthebhyas tasya prajñā pratiṣṭhitā

Kṛṣṇa (कृष्ण) is speaking.

The verse

And when he draws the senses in from their objects, as a tortoise draws in its limbs, his insight stands firm.

नेपालीमा

र जब ऊ कछुवाले अङ्ग तानेझैँ इन्द्रियहरूलाई तिनका विषयबाट भित्र तान्छ, उसको प्रज्ञा दृढ उभिन्छ।

Where it sits

The steady man can pull the senses back, the way a tortoise pulls in its legs. 2.59 will say that this is not the whole job, because the relish can stay after the objects have gone.

Split: यदा + संहरते + च + अयम् + कूर्मः + अङ्गानि + इव + सर्वशः + इन्द्रियाणि + इन्द्रिय-अर्थेभ्यः + तस्य + प्रज्ञा + प्रतिष्ठिता

yadā + saṃharate + ca + ayam + kūrmaḥ + aṅgāni + iva + sarvaśaḥ + indriyāṇi + indriya-arthebhyaḥ + tasya + prajñā + pratiṣṭhitā

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
यदाyadāindeclinablewhen.
संहरतेsaṃharatepresent, 3rd singular, middlehe draws in. From sam-hṛ (सम्-हृ).
चcaindeclinableand. It ties this man to the portrait already going.
अयम्ayamnominativethis one.
कूर्मःkūrmaḥnominativea tortoise.
अङ्गानिaṅgāniaccusative plurallimbs.
इवivaindeclinablelike, as.
सर्वशःsarvaśaḥindeclinablefrom all sides, entirely.
इन्द्रियाणिindriyāṇiaccusative pluralthe senses.
इन्द्रिय-अर्थेभ्यःindriya-arthebhyaḥablative pluralfrom the objects of the senses.
तस्यtasyagenitivehis.
प्रज्ञाprajñānominativeinsight.
प्रतिष्ठिताpratiṣṭhitānominative feminineset firm.

The phrases

yadā saṃharate ca ayam (यदा संहरते च अयम्) is the when. And when this man draws in. च + अयम् ca + ayam is cāyam (चायम्). What he draws in is delayed until the second line, so the simile can arrive first.

kūrmaḥ aṅgāni iva sarvaśaḥ (कूर्मः अङ्गानि इव सर्वशः) is the picture. As a tortoise draws in its limbs, from every side. कूर्मः + अङ्गानि kūrmaḥ + aṅgāni is kūrmo 'ṅgāni (कूर्मोऽङ्गानि). अङ्गानि + इव aṅgāni + iva is aṅgānīva (अङ्गानीव), because इ + इ i + i becomes ī (ई).

indriyāṇi indriyārthebhyaḥ (इन्द्रियाणि इन्द्रियार्थेभ्यः) is the real object, in the shape of the simile. The senses, from their objects. The ablative is what he draws them back from. इ + इ i + i joins the two words: indriyāṇīndriyārthebhyaḥ (इन्द्रियाणीन्द्रियार्थेभ्यः). The ḥ (ः) before tasya (तस्य) becomes s (स्).

tasya prajñā pratiṣṭhitā (तस्य प्रज्ञा प्रतिष्ठिता) is the refrain of 2.57.

Sanskrit in this line

iva (इव) is the simile-word, and it does not take a case. The two things compared stand in the same case as each other. Here the tortoise and the man are the drawers-in, and the limbs and the senses are what gets drawn. The verse spends the verb once, saṃharate (संहरते), and lets iva (इव) carry it onto the tortoise. You do not look for a second verb inside the simile.

Say it back

The animal, what it draws in, and what the man draws in from. If the senses come out as the things he goes toward, the ablative was missed.